There are a few things you can... but depending on your build it can be extremely difficult in avoiding kicks. Some things that will help though...
1: Get a longer 1h like the long espada and try not to get too close to enemies.. it takes some getting used to and does put you in danger of swinging and hitting air then taking a big 2h to the face.. but if you get the distance down its tough for them to kick you.
2: when approaching an enemy, NEVER walk in a straight line at them. Always come at them from an angle and try to keep circling around to make it harder for them to kick you... this is really hard if you have low athletics or too much armour though as you won't be fast enough to close into range on an angle and they can just S-Key and spam.
3: Related to #2... but... have 8 athletics and light armour... the mobility is your best chance to avoid kicks.
4: if you are in close with the enemy make sure you keep moving in unpredictable ways, and if the enemy tries to back up a bit, make sure again that you do not advance straight at him... it is VERY common for kickers to back off just a touch and then hold still while lining up a kick... always advance on awkward angles.
hopefully that helps a bit... being kicked is pretty much the worst thing ever and even if you employ all the tips I've listed here you will still get kicked occasionally because of the bullshit reach, area of effect and duration of kicks... but if you get used to dealing with kicks then you should hit them when they kick more often than you get kicked.